Mechanism of action of porphobilinogen deaminase. The participation of stable enzyme substrate covalent intermediates between porphobilinogen and the porphobilinogen deaminase from Rhodopseudomonas spheroides

Abstract

Highly stable labeled complexes are formed between porphobilinogen deaminase (from R. Sphaeroides) and stoichiometric amounts of [14C]porphobilinoge. On completion of the catalytic cycle by the addition of excess of substrate, the complexes yield labeled product and display all the properties expected from covalently bound enzyme intermediates involved in the deaminase catalytic sequence.